maximmasiutin TinyWeb up to 2.0 on Win32 php-cgi.exe os command injection

Summaryinfo

A vulnerability categorized as critical has been discovered in maximmasiutin TinyWeb up to 2.0 on Win32. Affected by this vulnerability is an unknown functionality of the file php-cgi.exe. Executing a manipulation can lead to os command injection. This vulnerability appears as CVE-2026-27613. The attack may be performed from remote. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in maximmasiutin TinyWeb up to 2.0 on Win32 and classified as critical. This vulnerability affects an unknown functionality of the file php-cgi.exe. The manipulation with an unknown input leads to a os command injection vulnerability. The CWE definition for the vulnerability is CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32. A vulnerability in versions prior to 2.01 allows unauthenticated remote attackers to bypass the web server's CGI parameter security controls. Depending on the server configuration and the specific CGI executable in use, the impact is either source code disclosure or remote code execution (RCE). Anyone hosting CGI scripts (particularly interpreted languages like PHP) using vulnerable versions of TinyWeb is impacted. The problem has been patched in version 2.01. If upgrading is not immediately possible, ensure `STRICT_CGI_PARAMS` is enabled (it is defined by default in `define.inc`) and/or do not use CGI executables that natively accept dangerous command-line flags (such as `php-cgi.exe`). If hosting PHP, consider placing the server behind a Web Application Firewall (WAF) that explicitly blocks URL query string parameters that begin with a hyphen (`-`) or contain encoded double quotes (`%22`).

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-27613 since 02/20/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1202.

Upgrading to version 2.01 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch d9dbda8db49da69d2160e1c527e782b73b5ffb6b is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-8763). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• maximmasiutin

Name

• TinyWeb

Version

• 2.0

License

• open-source

Website

• Product: https://github.com/maximmasiutin/TinyWeb/

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CPE 2.2info

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Once again VulDB remains the best source for vulnerability data.

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